WorldEngine

Each world on the server can carry its own gamerules, which override the vanilla values such as keepInventory and mobGriefing. A world can also have its own difficulty from peaceful through hard, its own default gamemode among survival, creative, adventure and spectator, and PvP can be switched on or off for each world without affecting the others.

Inventories are kept separate per world, and mob spawn rules can be set individually. Worlds unload after a configurable idle timeout, and a world with no players skips tick processing entirely. Saves are staggered so that several worlds do not write to disk at the same moment. A world is loaded only while a player is inside it, which helps a server with many worlds keep its tick rate steady. Commands need operator level 2, the gamemaster level, unless noted, and config changes take effect after a server restart.

Installing custom portal blocks on the client is needed for the portal feature. Server owners can set up two-way portals between worlds: a player builds a frame in each world, names it, and runs a command to link the two sides. Lighting a two-way portal takes a matching ore item on each side, a broken frame block switches the portal off, and a repaired frame can be lit again with a different ore item. The mod is published for the 1.21.11 game version only.